Fume extraction systems

ABSTRACT

A fume extraction apparatus ( 1 ) comprising an extraction pump, and the apparatus comprises a first interface ( 12 ) for connection to a process equipment, and a second interface ( 10 ) for connection to a system controller, wherein the apparatus comprises an intraconnection ( 15 ) to enable signals to be communicated between the first interface and the second interface.

TECHNICAL FIELD

The present invention relates generally to fume extraction systems.

BACKGROUND

Traditionally in industrial automated systems, sensors and actuators areindividually connected to the input/outputs of a programmable logicarray (PLC). This typically involves long cable runs from a control roomto the plant. FIG. 1 illustrates an example of a traditionalpoint-to-point wiring system configuration. If a new sensor or actuatorwere to be added to the system this would require the necessaryinput/output on the PLC and dedicated wiring installed, greatly reducingscalability. Each sensor or actuator requires a dedicated cable and PLCinput/output for communication of a single variable. Communication ofthis variable is only one-way, either from system component to PLC orPLC to system component. Analogue signals can be subjected to noise,especially in a manufacturing environment, affecting the accuracy of thesystem.

Fume extractors are often part of sub-systems in which a device performsa task which creates fumes as part of the industrial process. A typicalexample being a laser coding system in which the laser coding processcreates fumes which the fume extractor removes. These sub-systemsthemselves are often incorporated into larger systems controlled by asystem controller. The system controller communicates to the sub-systemcontroller (OEM device) which in turn controls the fume extractor asrequired.

Fume extraction systems comprise a series of filters such as multiplegraded particle filters and a gas filter which are housed in a singleunit, together with an extraction pump. The extraction pump drawscontaminated air into the unit through the filters to remove thecontaminants and output filtered air to the working area. Whensaturated, the filters, and in particular the gas filter must bereplaced. In environments where high rates of gas and vapour aregenerated, the filters will need to be replaced more often.

Reference is made to FIG. 2 which shows a fume extraction unit 100 and aPLC 110. The digital I/O interface provided by the fume extraction unitallows rudimentary control and monitoring capabilities. In the exampleshown, the fume extractor can be stop-started and the state of thesystem and its filters can be monitored. This configuration wouldrequire a minimum of four PLC inputs/outputs and their associatedwiring. Each additional fume extractor connected to the system wouldrequire additional input/outputs and wiring.

Reference is made to FIG. 3 which shows a typical example of a lasercoding sub-system (laser and fume extractor) 120 a and 120 b beingcontrolled by a main system controller (PLC) 110. Currently, it is knownto provide a simple digital interface to allow rudimentary monitoringand control of the extractor. In terms of inputs, these include stop andstart, and in terms of outputs, these include system states, filterstates and alarm states. Currently, it is known that for equipmentattached to the fume extractor, such as a coding laser, there isprovided a simple digital interface to allow rudimentary monitoring andcontrol functionalities.

An example, of a coding laser interface includes inputs for start andstop functions, and outputs for system ready, ready to mark, marking anderror.

We have devised an improved fume extraction apparatus in which interfaceand connectivity is provided for connected process equipment and acontrol module.

SUMMARY

According to a first aspect of the invention there is provided a fumeextraction apparatus comprising an extraction pump, and the apparatuscomprises a first interface for connection to a process equipment, and asecond interface for connection to a system controller, wherein theapparatus comprises an intraconnection to enable signals to becommunicated between the first interface and the second interface.

The signals may be representative of operational data and/or operationalcommands or requests.

The intraconnection may comprise an internal connection.

The intraconnection may comprise a switch.

Use of the intraconnection to convey signals between the first andsecond interfaces may be termed a bridging mode.

The intraconnection may comprise a switchable or fixed electricalconnection between the interfaces.

The intraconnection may be arranged to route signals between the firstinterface and the second interface, and vice versa.

The intraconnection may comprise a gateway.

The intraconnection may comprise a fieldbus gateway.

The intraconnection may comprise a Controller Area Network (CAN) bus orfieldbus.

A gateway of the intraconnection may be arranged to implement amessage-based communications protocol between the first interface andthe second interface, and in particular between one or more devicesconnected to each of the first and second interfaces.

The intraconnection may comprise circuitry which is capable ofcommunicating signals between the first interface and the secondinterface.

A gateway of the intraconnection may comprise a communications protocolconverter. The gateway may be arranged to allow communication betweendifferent communication/technology protocols.

At least one of the first interface and the second interface maycomprise an electrical interface. The electrical interface may comprisea socket or connector.

The intraconnection may be viewed as providing communication via theextraction unit between the first interface and the second interface.

An (internal) communications protocol between the first interface andthe second interface, may be different to the communication protocolbetween the second interface and the system controller.

At least one of the first and second interfaces may be configured toreceive a plug or connector.

The first and second interfaces may be physically distinct.

The first and second interfaces are preferably configured to connect toapparatus or devices which are external of the fume extractionapparatus. This may be in a detachably connectable manner.

The intraconnection is preferably internal of the fume extractor.

The process equipment may be equipment which, in use, generates fumes orhazardous vapour or particulate.

The first interface may be configured to be connected to a controller ofa process equipment.

The first interface may be arranged/configured to allow communication ofdata stored in a memory of the fume extraction apparatus to the processcontroller, for example upon interrogation of the same by the processcontroller.

The first interface may comprise an input/output (I/O) module.

The process equipment may be or comprise an automated (industrial)process equipment. The process equipment may comprise laser markingequipment.

The second interface may comprise a fieldbus.

The second interface may be arranged to handle a fieldbus communicationsprotocol.

The second interface may be arranged to communicate signals with theconnected controller by way of fieldbus communication protocol, forexample PROFIBUS (Process Field Bus).

The first interface may be configured to listen, in a listen mode, for asignal broadcast or output by the second interface, and vice versa,communicated over the intraconnection

The fume extraction apparatus of the invention may be viewed as havingfieldbus connectivity. Fieldbus may be considered as a network systemcommunication protocol which enables real-time distributed control ofelements, components and devices of the network, for example between acontroller and a system component. Fieldbus devices may share a commonbus. Fieldbus-operative or -compatible devices may be capable of beingadded to a system without additional hardware requirements from the PLCor system controller.

The second interface may comprise a CAN/PROFIBUS gateway.

The intraconnection may comprise a CAN bus.

The types of data and signals which are capable of being communicatedbetween the system controller and the process controller may include atleast one of the following:

Control signals

Operational status

Diagnostic data

Operational commands

Alarm signals

The system controller may be arranged to be capable of communicatingwith the process equipment to issue a start/stop command signal. Astart/stop signal is preferably a command signal indicative of aninstruction to start or stop the operation of the process equipment, forexample a RUN command.

The system controller may be viewed as a monitor for monitoring one ormore operational parameters of the fume extraction apparatus.Operational parameters may include flow rate, pump speed, temperatureand differential pressure.

The intraconnection may be configured such as to allow the systemcontroller to access data stored in at least one of the processcontroller and a memory of the unit controller of the fume extractionapparatus. A connection may be provided between the first interface andthe unit controller.

The intraconnection may be part of a master/slave system network. Thesystem network may be an automation network. The system network maycomprise a Controller Area Network (CAN).

The first interface may be a slave of a master/slave system network.

The second interface may be a slave of a master/slave system network.

The fume extraction apparatus may comprise a unit controller, which ispreferably located/housed within the apparatus. The unit controller maybe a master of a master/slave system network. The unit controller may beconfigured to determine a manner in which slaves communicate.

The intraconnection may be configured such that the first interface iscapable of being accessible by the unit controller and/or the secondinterface, for example access to at least one of its inputs/outputs.

The unit controller may be arranged to communicate with one or moresensors for monitoring operational parameters of the fume extractionunit.

The unit controller may comprise a user input and a user outputinterface. The unit controller may be arranged to allow a user to effectcontrol, effect operational settings/configurations and allow a user tointerrogate the unit for operational data. The unit controller maycomprise a data processor. The user output may comprise a visualdisplay.

The first interface may be viewed as a process equipment input/output(digital) interface. The first interface may comprise (internal) portswhich allow communication with the second interface.

The process equipment may comprise a sub-system which comprises aprocess controller and a controllable process device. Preferably theprocess controller is connected to the fume extraction apparatus.

The process controller may comprise a data processor which is arrangedto monitor operational parameters of the fume extraction apparatus. Theoperational parameters may include flow rates of air through theapparatus and filter saturation levels.

The process controller may be viewed as implementing operational controlof the fume extraction apparatus, in conjunction with at least thesystem controller.

According to a second aspect of the invention there is provided a fumeextraction system which comprises the fume extraction apparatus of thefirst aspect of the invention, a process equipment, including a processcontroller, and the system comprising a system controller. The systemcontroller may be an external unit or module. The system controller maybe arranged to effect or dictate control of the process equipment. Theprocess controller may be arranged to effect control of the fumeextraction apparatus, for example based on a control signal originatingfrom the system controller. The system controller may be connected tothe fume extraction apparatus by way of an external connection, whichmay comprise electrical wiring or cabling. The system controller maycomprise a separate physical entity to the fume extraction apparatus.

The fume extraction apparatus may comprise one or more features asdescribed in the description and/or as shown in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention will now be described, by way ofexample only, with reference to the following drawings.

FIG. 1 is an example of a traditional point-to-point wiring systemconfiguration.

FIG. 2 shows a fume extraction unit and a 110.

FIG. 3 shows a typical example of a laser coding sub-system.

FIG. 4 is a schematic representation of a fume extraction system.

FIG. 5 is a further schematic representation of the fume extractionsystem of FIG. 4.

FIG. 6 is a more detailed representation of the system shown in FIG. 5.

FIG. 7 is a representation of an alternative embodiments.

FIG. 8 is a schematic of multiple fume extraction units controlled by asingle system controller, and connected in series.

DETAILED DESCRIPTION

There is now described a fume extraction apparatus 1 which is providedwith improved interface, connectivity and control capabilities. Inoverview, the fume extraction apparatus 1 comprises an extraction pump,a housing, a user interface panel (which allows manual userinterrogation, user settings configuration and display of systeminformation and status), a fume inlet, an air outlet and filter modulesremovably located in the housing. The apparatus also comprisesoperational parameter monitoring sensors such as pressure sensors and/orflow sensors to enable monitoring of filter status and flow rates. Theapparatus 1 is arranged to be connected to a process equipment, such asa laser coding system 120 a and 120 b, and a process controller 110.During operation of the process equipment fumes are produced which aredrawn through the filters, and hazardous particulate is removed from theair, and the filtered air returned to the working area.

As will be described in more detail below, the fume extraction apparatus1 comprises an interface for connecting to the process equipment and aninterface for connection to the system controller. These interfaces 10and 12 are advantageously bridged by a connection 15 comprising internalcircuitry, allowing communication therebetween using communicationsignalling protocols, and in turn allowing enhanced and streamlinedcontrol and data exchange capabilities during operation of the fumeextraction apparatus.

With reference to FIGS. 4 and 5, the fume extraction unit 1 comprises afirst interface 12 and a second interface 10. The interface 10 comprisesan electrical connector (such as an electrical socket) arranged toreceive a counterpart connector, such as an electrical plug. Theinterface 12 also comprises an electrical connector, which enablesconnection with the process equipment controller 120 a.

The system controller 110 is arranged to monitor operational parametersof the extraction unit 1, such as air flow rates through the unit 1,filter saturation status, alarm conditions and fault conditions. Thecontroller includes a memory and data processing capability to updaterelevant operational status accordingly. The system controller is anexternal, separate unit to the fume extraction apparatus 1. The systemcontroller 110 processes data received from the operational parametersensor via a unit controller 14 which is contained internally of theapparatus 1.

In this arrangement, various data and signalling is transmitted via theconnection 15, which is internal of the fume extraction unit 1. Theconnection 15 provides connectivity between the first interface 12 andthe second interface 10. In particular, the gateway interface 10 isarranged to translate signals between CAN and PROFIBUS communicationsprotocols. This includes communication of various control/command,status and data signals. In particular, the process controller 120 a iscapable is outputting SYSTEM READY, READY TO MARK, MARKING, ERRORoperational status signals to the system controller 110.

In the opposite sense, the system controller 110 can send the followingoperational command signal to the process controller 120 a, START/STOP.Therefore, should the controller 110 determine a status which isindicative of the unit 1 not being operated, the controller 110 outputsa signal via the interface 10, across the connection 15, through theinterface 12, and to the process controller 120 a. A data processor ofthe process controller, is then operative to output a control signal viathe interface 12 to the unit 1 which causes the unit to start or stopoperation (for example by way of a relay housed in the unit 1).Similarly, when the process controller 120 a determines that the processequipment is ready to be operatively functional it will output a READYTO MARK signal. The signal passing via the interfaces 12 and 10 and theconnection 15 reach the system controller 110. In response, assumingthat inhibitive status of the unit 1 is determined, the systemcontroller 110 can respond with a START command to the processcontroller 120 a.

Additionally to signals received from the system controller 110, theprocess controller 120 a is capable of receiving operational statussignals directly from the fume extraction unit. This includes SYSTEM OKstatus and FILTER WARNING status.

The interface 10 comprises a fieldbus interface, and the intraconnectionis configured to communicate using the CANopen protocol to the interface12, and vice versa. It will be appreciated that the process controller120 a is connected to the extraction apparatus 1 also by way of afieldbus connection. It will also be appreciated that data andsignalling between the interface 10, the interface 12 and the controller14 are by way of the CANopen protocol.

Reference is made to FIG. 6, which shows the system components and theconnections in more detail. The (Customer I/O) Interface 12 in essencecomprises a configurable digital I/O module with a CANopen slaveinterface. The fieldbus gateway of the interface 10 is used to allow theapparatus 1 to communicate with a fieldbus of a different type. Thefieldbus gateway in this example is configured to have its CANopeninterface acting as a slave. The controller unit 14 acts as a CANopenmaster (or system hub), and is connected to the interface 12 by way ofintraconnection 16. The controller 14 configures how slaves communicateon the network.

In use, the interface 12 is configured to broadcast the state of its(digital) inputs whenever they change state. The state of the inputs canalso be polled if required.

The unit controller 14 is configured to listen to the broadcastedmessages from the interface 12 that control the apparatus (i.e. Fumestart/stop).

The fieldbus gateway of the interface 10 is configured to listen to theinterface 12 broadcasted messages that are intended for the systemcontroller 110 (PLC). The fieldbus gateway 10 relays these messages tothe system controller 110.

The unit controller 14 is configured to broadcast its ‘System OK’ and‘Filter Warning’ states whenever either of these status changes. This isan example as for other systems there may be greater or fewer signals tobe sent via the interface 12.

The fieldbus gateway of the interface 10 is configured to broadcast anymessages it receives from the system controller 110.

The interface 12 will be configured to listen for the messages intendedto be output to the attached equipment (in this case a lasercontroller). On receipt of a message it will output the stateaccordingly via its digital output interface.

FIG. 7 shows an alternative embodiment in which substantially the samefunctionality is realised without the interface 12 (which may also betermed a ‘Customer I/O Interface’) being a standalone board or module,namely that the (modified) unit controller 140 of the fume apparatus hasembedded into it (at least from a functionality perspective) theinterface 12, and comprising an internal connection 150 with thecontroller 140. The extraction unit 1 can physically connect to thelaser's data communication lines. The unit 1 is operative to relay therequired data to the (PLC) 110 via the fieldbus gateway of the interface10.

Advantageously, additional fume extractors can easily be added to anexisting system greatly improving scalability as compared to the knownapproaches.

It will be appreciated that in this way, access to both the processcontroller 120 a and the data stored in the extraction apparatus 1, isnow advantageously readily available to the system controller 110. Thisprovides a greatly simplified connection configuration as compared toprior art arrangements. Also, this allows the extraction apparatus 1 tobe directly controlled by way a single external fieldbus interface,namely interface 10, by the system controller 110. Reference is made toFIG. 8 which shows how a single system controller 110 can be used tocontrol multiple connected fume extraction units, connected together inseries by way of wires/cabling 50. Instead of requiring respectivemultiple wiring/cabling from the system controller 110 to eachextraction unit, the system controller requires only connection to oneunit.

The use of the fieldbus connection enables users to easily achieve aparticular system configuration, be it simple or more complex. It willbe appreciated that use of the interface 12 is not limited to lasercoding equipment, and so the fume extraction apparatus can be used witha range of attached process equipment types.

The fieldbus connection has several benefits over a simple digital I/Ointerface of the prior art such as, complex data transfer, scalability,easy integration into existing systems and simpler wiring requirements.Multiple sub-systems can be connected to a larger system withoutrequiring additional system controller I/O ports and the associateddedicated wiring.

The ability of the interface 12 to be (directly) controlled via the(external) fieldbus interface 10 allows equipment connected to theapparatus to inherit fieldbus capabilities through its digitalinterface. In laser applications, complete system control is achievedvia a single fieldbus connection. This allows laser equipment to besimply and quickly integrated.

1. A fume extraction apparatus comprising an extraction pump, theapparatus comprising: a first interface for connection to a processequipment, and a second interface for connection to a system controller,wherein the apparatus comprises an intraconnection to enable signals tobe communicated between the first interface and the second interface. 2.A fume extraction apparatus as claimed in claim 1 in which the signalsare representative of operational data and/or operational commands orrequests.
 3. A fume extraction apparatus as claimed in claim 1 in whichthe intraconnection is arranged to route signals between the firstinterface and the second interface, and vice versa.
 4. A fume extractionapparatus as claimed in claim 1 in which the bridge interface isarranged to implement a message-based communications protocol betweenthe first interface and the second interface.
 5. A fume extractionapparatus as claimed in claim 1 in which the first interface isconfigured to allow communication of data stored in a memory of the fumeextraction apparatus to the process controller, for example uponinterrogation of the same by the process controller.
 6. A fumeextraction apparatus as claimed in claim 1 in which at least one of thefirst and second interfaces are arranged to carry a fieldbuscommunications protocol.
 7. A fume extraction apparatus as claimed inclaim 1 in which the second interface is arranged to communicate signalswith the system controller by way of fieldbus communication protocol. 8.A fume extraction apparatus as claimed in claim 1 in which the types ofdata and signals which are capable of being communicated between thefirst interface and the second interface include at least one of controlsignals, operational status, diagnostic data and operational commands.9. A fume extraction apparatus as claimed in claim 1 in which the firstand second interfaces are such that the system controller is arranged tobe capable of communicating with the process equipment to issue astart/stop command signal in relation to controlling the operationalstatus of the fume extraction apparatus.
 10. A fume extraction systemwhich comprises the fume extraction apparatus of claim 1, a processequipment, including a process controller, and the system comprising asystem controller.